• Journal of the Korean earth science society
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• v.35 no.6
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• pp.439-466
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• 2014

Since the unification of the diverse oceanic current maps of the East Sea in secondary school science textbooks has recently been accomplished, there have been increasing requirements for the production of a current map of the Yellow Sea (YS) and the East China Sea (ECS). This study, as its first attempt, facilitated the prospective production process of the unified oceanic current maps in YS and ECS by analyzing the maps of scientific articles and those of the present textbooks as of 2014. First of all, the analogue current maps of the textbooks and scientific articles were digitalized to retrieve the characteristics of current maps quantitatively and to make intercomparison of the maps. The currents of both YS and ECS such as the Kuroshio Current, the Taiwan Warm Current, the Tsushima Warm Current, the Yellow Sea Warm Current, the Chinese Coastal Current, the Korea Coastal Current, and the Changjiang River Flow were selected and analyzed. We made 18 items to investigate the paths of the currents. Analyses of the oceanic current maps of secondary school science textbooks and scientific articles with respect to the selected criteria revealed that the current maps of the textbooks were considerably different from the up-to-date knowledge of the current maps acquired from the scientific articles. In addition, since the currents of YS and ECS have strong seasonality, we suggest that they should be presented with at least two current maps for summer and winter in the textbooks, which may go through active discussions among experts.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1069-1077
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• 2009

Lately, it is an important concern in water resources research to maintain a stable water supply according to a future climate change and an increase in water use. In Han-River basin, approximately 10 % of water resources that is provided the capital region (Gyeonggi, Seoul etc.) has been reduced as a consequence of the construction of Imnam Dam (storage volume: 27 billion $m^3$) located in the upper Hwacheon Dam upstream area. Therefore, streamflows have decreased in Bukhangang basin, but it could not be evaluated quantitatively. In this study, SWAT-K which is the physically based long-term runoff simulation model, was used in order to evaluate the effect of Imnam Dam on the reduced inflow to Hwacheon Dam according to the change of hydrological condition in the upstream area of Hwacheon Dam. For the model input data of North Korea area, meteorological data of GTS (Global Telecommunication System) were used, and soil maps by FAO/UNESCO (2003) were applied. Temporal variations of water resources is investigated with comparison of observed and simulated inflows at Hawcheon Dam site. Also, annual, monthly, seasonal decreases in water resources were evaluated using the flow duration analysis of simulated streamflows with or without Imnam dam.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4B
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• pp.221-232
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• 2012

In this study, the model enhancing the safety of reservoirs and reducing the downstream flood damage by reservoirs system operation during abnormal flood was developed. Linear programming was used for the optimal reservoirs system operation during an abnormal flood and fuzzy inference system was introduced to solve the uncertainty problem which is included in hydrological factors like inflow, water level and inflow variation of reservoir operation. The linear programming model determined the optimal reservoir system operation rules and could be used in situation where water demands varies rapidly during the abnormal flood events using fuzzy control technique. In this study, the optimal reservoirs system operation for Andong and Imha reservoirs located in the upper basin of Nakdong river was performed in order that the design flood discharge at Andong city would not be exceeded for the design flood of 100 year and PMF(Probable Maximum Flood). And the model that determines the release according to the downstream flow discharge, the reservoir storage, the inflow and the inflow variation of each reservoir was developed using the optimal system operation result and fuzzy control technique. The developed model consisted of 224 fuzzy rules according to the conditions of Andong reservoir, Imha reservoir and Andong city. And the release from each reservoir could be determined when the current data are used as input data through the developed GUI.

• Journal of Korea Water Resources Association
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• v.49 no.6
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• pp.519-528
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• 2016

Frequently torrential rain is occurred by climate change and urbanization. Urban is formed with road, residential and underground area. Without detailed topographic flooded analysis consideration can take a result which are wrong flooded depth and flooded area. Especially, flood analysis error of population and assets in dense downtown is causing a big problem for establishments and disaster response of flood measures. It can lead to casualties and property damage. Urban flood analysis is divided into sewer flow analysis and surface inundation analysis. Accuracy is very important point of these analysis. In this study, to confirm the effects of the elevation data precision in the process of flooded analysis were studied using 10m DEM, LiDAR data and 1:1,000 digital map. Study area is Dorim-stream basin in the Darim drainage basin, Sinrim 3 drainage basin, Sinrim 4 drainage basin. Flooding simulation through 2010's heavy rain by using XP-SWMM. Result, from 10m DEM, shows wrong flood depth which is more than 1m. In particular, some of the overflow manhole is not seen occurrence. Accordingly, detailed surface data is very important factor and it should be very careful when using the 10m DEM.

• Clean Technology
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• v.7 no.4
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• pp.251-263
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• 2001

This study was conducted to provide a basic information for recovery plan of Seung-Gi Stream which is a major stream of Incheon metropolitan area. Source and characteristics of pollutants were analyzed and studied. Samples were taken 10 rounds in 5 sections in Seung-Gi stream. Annual pollutants loads and sectional characteristics of pollutants loads were investigated regarding flow rate, pH, DO, SS, $BOD_5$, $COD_{Cr}$, T-P, TKN and concentrations of Zn, Cd, Cu, Cr atoms which enter into Seung-Gi stream during rainy and dry season respectively. As one came close to the Nam-Dong Industrial Complex, sectional discharge loads were heavy and water quality was failed to meet the standard by "Environmental Standard of River Quality". As a result, heavy load of pollutants in Seung-Gi stream was considered to influence negatively the sea water quality of Incheon. Solution plans to solve problems are as follows. First, circulation of treated water at Seung-Gi WWTP(Wastewater Treatment Plant) and retreated water by URC(ultra rapid coagulation) process treat with that. Second, sewage and wastewater is gathered, make it disposed. After then, we circulate treated water. If solution plans be applied, we can predict water quality. Then we could grope for how make to recovery role of Seung-Gi stream as stream.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.76-83
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• 2017

Fish respond sensitively to light, so it is possible to develop fish management technology using this feature. In this study, we developed a light-based fish barrier and analyzed itsblocking effect using the difference in illuminance for the major fish species in Korea, bass and bluegill. The light was generated by a light emitting diode and the facility was installed vertically from the bottom. Considering the fish's ability to travel upstream, the flow rate was divided into three stages (0.2, 0.1, and 0.05 m/s). To prevent the learning effect, an experiment was carried out with fish that had rested for more than one day in a rearing tank. The experiment was carried out in such a way as tocompare the number of fish which travelled upstream after the introductionof the fish barrier and that of the fish which travelled upstream after itsremoval. It was also carried out after sunset to increase the effectiveness of the barrier. According to the results of the experiment, the fish blocking effect depending on the difference in illuminance was high and, overall, the blocking rate for bass was lower than that for bluegill. Based on the total size of the experimental population, the blocking rates for bass and bluegill were 96.33% and 99.00%, respectively. Based on the number of fish that travelled upstream, the blocking rates for bass and bluegill were 91.73% and 98.73%, respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.4
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• pp.499-505
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• 2015

Trend Impact Analysis(: TIA) is an advanced forecasting tool used in futures studies for identifying, understanding and analyzing the consequences of unprecedented events on future trends. An adaptive neuro-fuzzy inference system is a kind of artificial neural network that integrates both neural networks and fuzzy logic principles, It is considered to be a universal estimator. In this paper, we propose an advanced mechanism to generate more justifiable estimates to the probability of occurrence of an unprecedented event as a function of time with different degrees of severity using Adaptive Neuro-Fuzzy Inference System(: ANFIS). The key idea of the paper is to enhance the generic process of reasoning with fuzzy logic and neural network by adding the additional step of attributes simulation, as unprecedented events do not occur all of a sudden but rather their occurrence is affected by change in the values of a set of attributes. An ANFIS approach is used to identify the occurrence and severity of an event, depending on the values of its trigger attributes. The trigger attributes can be calculated by a stochastic dynamic model; then different scenarios are generated using Monte-Carlo simulation. To compare the proposed method, a simple simulation is provided concerning the impact of river basin drought on the annual flow of water into a lake.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.799-803
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• 2006

국내 유량자료는 아직 장기간의 유출량 자료가 확보되어 있지 못하며, 미계측 유역에서의 유출량에 대한 해결책이 마련되어 있지 못한 실정이다. 따라서 국가 수자원 계획이나 효율적인 물관리를 위한 장기유출해석을 위해 유출모형이 사용되고 있다. 본 연구에서는 한국건설기술연구원에서 개발한 SWAT-K 모형을 이용하여 팔당댐 지점을 최종출구점으로 하는 한강유역의 자연유출량을 산정하고자 하였다. 여기에서는 유역내 인위적인 저류시설물인 댐이 없는 상태를 자연유량이 가정하고 팔당댐 지점에서의 자연유량을 산정하여 그 결과를 검토하였다. 대상유역으로 선정된 한강유역(팔당댐 상류유역)의 경우, 유역내 다목적댐, 용수전용댐, 발전전용댐 등 다수의 댐이 위치하고 있다. 기존 사용되어 오고 있는 집중형 모형으로는 대상유역 내의 댐을 고려할 수 없으며, 유역출구점에서의 유출량만을 모의할 수 있다. 그러나, SWAT-K 모형은 유역내 댐고려가 가능한 저수지 모듈을 포함하고 있으며, 유역내 사용자가 원하는 지점에서의 유출량을 모의할 수 있다. 먼저 자연유량을 산정하기 앞서, 댐이 위치하고 있는 대상유역에 대하여 모형에서 고려할 수 있는 댐운영 방법별로 모의유량과 관측유량을 이용하여 댐운영 모의능력을 검증하였다. 또한, 대상유역의 최종출구점인 팔당댐 지점과 유역내에 위치하고 있는 댐지점에 대하여 각각 관측유량과 모의유량을 비교 검토하여 모형의 적용성을 확인할 수 있었다. 따라서, 최종적으로 보정된 매개변수를 이용하여 댐이 없는 상태의 한강유역에 대하여 자연유량을 산정하여, 팔당댐 지점을 중심으로 댐의 유무에 따른 유량의 변화를 고찰하였다. 시범수행에서는 10개의 트렌치를 설치하여 그 효과를 분석하였다. 9번 소유역 145번 지점의 유황을 분석한 결과 저수량$(Q_{275})$은 $0.0177m^3/s$에서 $0.0190m^3/s$로, 갈수량$(Q_{355})$은 $0.0176m^3/s$에서 $0.0189m^3/s$로 약 7%가 증가하는 것으로 분석되었다. 결과로부터 침투 트렌치는 저수량 및 갈수량을 증가시키는 보조수단이 될 수 있다.해 보았다. 뿐만 아니라 이와 관련된 수문요소기술을 확보할 수 있을 것이다.역의 물순환 과정을 보다 명확히 규명하고자 노력하였다.으로 추정되었다.면으로의 월류량을 산정하고 유입된 지표유량에 대해서 배수시스템에서의 흐름해석을 수행하였다. 그리고, 침수해석을 위해서는 2차원 침수해석을 위한 DEM기반 침수해석모형을 개발하였고, 건물의 영향을 고려할 수 있도록 구성하였다. 본 연구결과 지표류 유출 해석의 물리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다. 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더

• Journal of Korea Water Resources Association
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• v.40 no.5
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• pp.383-396
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• 2007

The studies on efficiency of flood control reservoir has been introduced into four categories including direct flood control contribution by reservoir, flow-duration change and environmental-ecological change in downstream of dam and flood damage estimation of flood plain. In spite of all the previous approaches, the quantification of the effect of reservoir on the flood control in planning stage is quite complex due to lack of a standard for quantifying feasibility of project. In this study, we develop a methodology that can clearly and accurately quantify the flood damage reduction together with the existing flood level reduction at downstream. The proposed approach uses three appraisal standards of flood control: 'potential safety', 'relative risk' and 'absolute risk' according to the risk by stage. The developed methodology was applied to the Namhan river basin with the storm event of July, 2006. The result shows the damage reduction of 4,189 billion won was estimated. The economic benefits for the flood control effect by dam will greatly contribute to the public understanding of the importance and the effect of the flood control by dam.

• Journal of Korea Water Resources Association
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• v.45 no.11
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• pp.1131-1141
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• 2012

In this study, factors that influence water supply capacities of dams are extracted using factor analysis, and multiple regression equations for estimating water supply capacities of dams are developed using the analysis results. Twenty-one multi-purpose dams and twelve Municipal and Industrial (M&I) water supply dams are selected for case studies, and eight variables influencing water supply capacities of dams, namely: watershed area, inflow, effective reservoir storage, grade on amount of M&I water supply, grade on amount of agricultural water supply, grade on amount of in-stream flow supply, grade on river administration, and grade on average rainfall, are determined. Two case studies for multi-purpose dams and M&I water supply dams are performed, employing factor analysis, respectively. For the two cases, preliminary tests, such as reviewing matrix of correlation coefficient, Bartlett's test of sphericity, and Kaiser-Meyer-Olkin (KMO) test, are conducted to evaluate the suitability of the variables for factor analysis. In case of multi-purpose dams, variables are grouped into three factors; M&I water supply dams, two factors. The factors are rotated using Varimax method, and then factor loading of each variable is computed. The results show that the variables influencing water supply capacities of dams are reasonably selected and appropriately grouped into factors. In addition, multiple regression equations for predicting the amounts of annual water supply of dams are established using the factor scores as explanatory variables, it is identified that the models' accuracies are high, and their applications to determining effective storage capacity of a dam during dam planning and design steps are presented. Consequently, it is thought that the variables and factors are useful for dam planning and dam design.